Here are eight issues to research and discuss before the debate even begins, courtesy of Beau Kilmer, co-director of the Rand Drug Policy Research Center and a co-author of "Marijuana Legalization: What Everyone Needs to Know."

Kilmer calls his recommendations the Eight P's.

1. Production: Where and how will the marijuana be grown? On existing farms? Specialty farms? Indoors? Just who grows it and how is that determined?

2. Profit: How will it be sold? Like alcohol and tobacco, by big companies with high-powered lobbyists? By small independent growers and shops? By the state?

3. Promotion: How will the marketing of marijuana be regulated? If the regulations are too strict, they might face free speech challenges. If they're too loose, your child may wonder what's wrong with smoking – or eating – marijuana.

4. Prevention: People say legalize it, tax it and pay for prevention. "But it seems like people want to have that all at once," says Kilmer. Communities must develop strategies for education and prevention well before they legalize marijuana.

5. Potency: Some THC (the active ingredient in marijuana) can get you high and make you paranoid. Much of the pot sold in Colorado is pretty strong, with a THC percentage of about 10 to 20 percent, compared to 3 percent in the 1970s. Should the THC be limited, as is being discussed in the Netherlands? Another chemical in marijuana – cannabidiol, or CBD – may offset some of the effects of the THC. Should we put a limit on the ratio of THC to CBD?

6. Purity: In addition to potency, marijuana should be tested for mold and pesticides, says Kilmer. Will products like hash oil – legal in Colorado – be allowed in E-cigarettes, tobacco products or alcohol?

7. Price: How will the price be set? If it's too low, more people will use marijuana –including people from neighboring states. If it's too high, because of high taxes, there may be a black market.

8. Permanency: When a state develops regulations, it must build flexibility into them so the laws can be changed, says Kilmer. This is particularly important if lobbyists play a role in creating laws that benefit the industry – laws those lobbyists will fight to keep in place.